Electric switch



April 19, 1938. J. A. CLINTON ELECTRIC SWITCH Filed April 15, 1937 2Sheets-Sheet 2 fi'fighfiturngy Patented Apr. 19, 1938 UNITED STATESPATENT OFFICE ELECTRIC SWITCH necticut Application April 15, 1937,Serial No. 137,091

4 Claims.

The invention relates to electric switches, and more particularly toswitches. which include circuit overload protecting means such as fuses.

The principal object of the invention is to provide a switchconstruction including a casing therefor wherein there is provided amain cover which when closed prevents access to the switch circuitconnectors but does permit access to certain other parts of the switch,and on which is mounted an auxiliary cover openable therewith and alsoindependently thereof and which carries an electrical conductor adaptedto electrically connect the switch contacts under certain conditions.

From the following specification other objects and advantages of theinvention will be apparent to those skilled in the art.

In the accompanying drawings I have shown the embodiment of theinvention which I now deem preferable, but it will be understood thatthe drawings are intended for illustrative purposes only and are not tobe construed as defining or limiting the scope of the invention, theclaims forming a partof this specification being relied upon for thatpurpose.

In the drawings:

Fig. 1 is a front elevation of a switch embodying the principles of theinvention.

Fig.2 is a view similar to Fig. l but showing the auxiliary cover inopen position.

Fig. 3 is a view similar to Fig. 1 but showing both covers in openposition.

Fig. 4 is a sectional view taken on the line 44 of Fig. 1 with certainparts broken away to more clearly show the construction.

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1.

In accordance with the invention a casing is provided which may be ofany desired type and in the drawings I have illustrated the casing ascomprising a channel member I having removable side walls 2. The channeland side walls may be provided with such knockouts as may be considereddesirable. I now prefer the form of casing illustrated because it may beincorporated in a troughing system such as shown in the patent to SachsNo. 1,758,981 issued May 20, 1930.

In the casing I mount means for supporting the several elements of theswitch. An insulating block 3 constitutes such a supporting means and itis stationarily mounted by screws 4 on a bracket 5 which is in turnsecured in the casing.

In the illustrated embodiment I have shown twoidentical switches andassociated circuits but it should be understood that any number ofswitches could be provided and that they could be of identical ordifferent constructions as desired. As my two switches are identical Iwill only describe one.

On the block 3 are mounted line and load circuit connectors 6 and 1,respectively, which are preferably so mounted as to be readilyaccessible under certain conditions for connection purposes. On theblock 3 I also mount at least one switch contact and provide means forelectrically connecting this contact with one of the circuit connectors.I have shown two switch contacts 8 and 9 mounted on the block and eachone is electrically connected with a circuit connector. At least one ofthe contacts is so positioned that a person would not ordinarily touchit and thereby receive a shock. In the preferred constructionillustrated both of the contacts 8 and 9 are so positioned as toeifectively prevent accidental contact therewith. These contacts arepreferably embedded in the block 3 in recesses l0 which open into thesurface ll of the block and form the apertures I2 therein, the contact 8being secured to the block by a screw 13. It should be noted that thesecontacts in the preferred construction lie behind the plane of thesurface I l, and are not only positioned in recesses in the block butare also aligned with the apertures I2 in the surface II. I do not,however, wish to limit myself to either of these details, the same beingmerely preferred rather than critical.

A fused type of switch is shown, this being the form of switch to whichthe principles of my invention are particularly applicable. Inaccordance with the invention the fuse is preferably interposed in thecircuit connecting one of the switch contacts with the load circuitconnector 1 and is so positioned as to be accessible for replacement. Inthe drawings I have shown a fuse receiving means M which is mounted onthe block 3 to hold a fuse in such a position that it is accessiblc fromthe front of the casing for replacement. A center fuse contact 15, whichis screw threaded, is secured to an angular extension it on the contact9 to thereby electrically connect the two and to secure the contact 9 tothe base. The threaded she-l1 contact [4 is connected to the loadcircuit connector 'I.

In accordance with the invention an openable main cover having anaperture therein is provided for closing the front of the casing. Thecover is so related to the casing and block 3 that, when closed, accessto the circuit connectors 6 and l is prevented but access to at least aportion of the block is permitted. The main cover IT is hinged to thecasing as indicated at l8 and includes an apertured portion 19. It isapparent from the drawings, note Figs. 2 and 4 in particular, that Ihave shown a construction for effectively preventing access to thecircuit connectors while permitting access to at least a portion of theblock 3, and more particularly to at least that portion of the block onwhich a fuse is adapted to be mounted so that the fuse may be replacedwithout opening the main cover.

The main cover may be secured in closed position in various Ways but Ihave shown a construction which I now consider preferable. The block 3has a. hole 29 formed therein in which is secured a nut 2!. The maincover has a hole therethrough at 22 and a bolt 23 projecting through thehole for engaging the threads of the nut 2! constitutes a releasablemeans for securing the main cover in closed position. The bolt may, ofcourse, be omitted if desired. The casing is also provided with theapertured spring latch 24 which is adapted to project through a hole 25in the cover when closed.

I provide an auxiliary cover for closing the aperture in the main cover,the auxiliary cover being mounted on the main cover so as to be movableto expose the aperture in the latter and also so as to be movable withthe main cover. The movement of the auxiliary cover with respect to themain cover may be of any desired type, but this will be dependent uponother details of construction. In the illustrated and now preferred formof the invention, an auxiliary cover 26 is hinged to the main cover at21 and includes an offset or domed portion 28. The auxiliary cover 26 islarger than the aperture in the main cover and, therefore, when closedserves tonot only cover the aperture but to also cover the main coversecuring bolt 23. The main cover is preferably ofiset at 29 to permitthe edges of the auxiliary cover to lie flush with the outer surface ofthe main cover and may be apertured .as at 30 to receive a spring latch31 on the auxiliary cover. It is apparent that the two covers I! and 26will move as a unit when the main cover is opened. A handle, such asshown at 32 may be provided on the auxiliary cover.

The auxiliary cover has mounted thereon, and insulated therefrom, anelectrical conductor which projects rearward therefrom. This conductoris so positioned and dimensioned that it electrically connects theswitch contacts in the casing when both the main and auxiliary coversare closed and is electrically disconnected from at least one of themwhen either the main or auxiliary cover is open. In the embodiment shownan electrical conductor 33 is secured to the auxiliary cover 26 by meansof an insulating block 34 which is secured to the offset portion 28 ofthe cover. In the illustrated form, the switch contacts 8 and 9 aremounted in separate recesses in the block 3 and the conductor 33 isaccordingly provided with two legs 35 which are adapted to projectthrough the apertures l2 in the surface I I of the block to electricallyconnect the switch contacts.

The ends of the switch contacts 8 and 9 and the legs 35 are preferablybeveled to provide co operating cam surfaces 36 and 31 for .assuring theproper engagement of these members when the conductor legs 35 are beingmoved into engagement with the switch contacts.

In using my device, either or both of the covers may be sealed shut bypadlocks, for example, secured to the latch 24 and rings 38, and themain cover may, if desired, be additionally fastened by the bolt 23.

The particular fused switch shown is adapted for use with a three wiresystem and for this reason I have shown a solid neutral 39 mounted onthe block 3.

The operation of the device illustrated will now be described, assumingfirst that the switch is suitably mounted and properly connected in anelectrical circuit. If the auxiliary cover is sealed in closed position,the seal is first removed. By means of the handle 32 the auxiliary cover26 may now be moved to open position and while being so moved theconductor 33 is moved out of engagement with the switch contacts 8 and 9to thereby electrically disconnect them. As the contacts 8 and 9 arepositioned behind the surface ll there is little or no danger ofaccidentally touching these contacts. Also with just the auxiliary coveropen no access may be had to the g0 circuit connectors 6 and I. Theconnector 1 is preferably connected to the load side of the circuit andconsequently with the auxiliary cover open so as to expose the fuse forreplacement the fuse contacts l4 and I5 are electrically dead.

The fuse may now be replaced without danger of shock to the person soreplacing it. The auxiliary cover may now be closed, movement of theconductor 33 being simultaneously effected to electrically connect theswitch contacts 8 and it is apparent that the switch contacts 8 and 9\will be electrically disconnected when the main,

cover is open to expose the circuit connectors.

It is of course obvious that various changes in details of constructionwithin the scope of the invention will be apparent to those skilled inthe 40 art.

What I claim is:

i. The combination in a fused electric switch, of a casing, aninsulating block stationarily mounted within the casing .and having afront 4,5

surface, an openable main cover for the casing having an openingtherein, the edges of the opening substantially fitting the block andthe cover thus cooperating with the block to entirely close the casingwith only the front face of the block exposed, line and load circuitconnectors mounted on the block behind the cover, two switch contactsmounted on the block behind the front surface thereof so as to besubstantially protected thereby from being accidentally touched, one ofsaid contacts being electrically connected within the casing with onecircuit connector, fuse receiving contacts mounted on the block adjacentthe front surface thereof so as to be accessible through the coveropening for fuse replacement,

the said fuse contacts being electrically connected within the casingwith said other switch contact and with the other circuit connectorrespectively, an openable auxiliary cover mounted to be movable with themain cover and normally serving to close the opening therein and tocover said exposed front surface of the block, and an electricalconducting member carried by the auxiliary cover and insulated therefromand. being so formed and positioned as to engage and electricallyconnect the switch contacts when the auxiliary cover is closed and toelectrically disconnect said contacts when either the main or auxiliarycover is open.

2. The combination in a fused electric switch,

of a casing, an insulating block stationarily mounted within the casingand having a front surface with at least one relatively small aperturetherein, an openable main cover for the casing having an openingtherein, the edges of the opening substantially fitting the block andthe cover thus cooperating with the block to entirely close the casingwith only the front face of the block exposed, line and load circuitconnectors mounted on the block behind the cover, a switch contactmounted on the block behind the front surface thereof in alignment withsaid aperture therein so as to be substantially protected from beingaccidentally touched, said contact being electrically connected withinthe casing with the line circuit connector, a second switch contactmounted on said block, fuse receiving contacts mounted on the blockadjacent the front surface thereof so as to be accessible through thecover opening for fuse replacement, the said fuse contacts beingelectrically connected within the casing with said second switch contactand with the load circuit connector respectively, an openable auxiliarycover mounted to be movable with the main cover and normally serving toclose the opening therein and to cover said exposed front surface of theblock, and an electrical conducting member carried by the auxiliarycover and insulated therefrom and being so formed and positioned as toengage and electrically connect the switch contacts when the auxiliarycover is closed and to electrically disconnect said contacts when eitherthe main or auxiliary cover is open.

3. In combination, a casing, an insulating block stationarily mountedwithin the casing, circuit connectors mounted on said block, at leastone pair of switch contacts mounted on said block so as to besubstantially protected from being accidentally touched, a switchingmember movable to electrically connect and disconnect said pair ofswitch contacts, means for electrically connecting one switch contactwith one of said circuit connectors, said means including a fusereceiving device mounted on said block, an openable main cover forclosing the front of the easing, said cover including an aperturedportion so positioned with respect tosaid block that when the cover isclosed access through the front of the casing may be had to said fusereceiving device for fuse replacement but not to the circuit connectors,releasable means for securing the main cover in closed position, and anopenable auxiliary cover for closing the aperture in the main cover andfor covering the main cover securing means, said auxiliary coverincluding means by which it may be secured in closed position againstunauthorized opening.

4. In combination, a casing, an insulating block stationarily mountedwithin the casing, circuit connectors mounted on said block, at leastone pair of switch contacts mounted on said block so as to besubstantially protected from being accidentally touched, a switchingmember movable to electrically connect and disconnect said pair ofswitch contacts, means for electrically connecting one switch contactwith one of said circuit connectors, said means including a fusereceiving device mounted on said block, an openable main cover forclosing the front of the casing, said cover including an aperturedportion so positioned with respect to said block that when the cover isclosed access through the front of the casing may be had to said fusereceiving device for fuse replacement but not to the circuit connectors,releasable means for securing the main cover in closed position, and anopenable auxiliary cover for closing the aperture in the main cover andfor covering the main cover securing means, said means and auxiliarycovers including cooperating means by which they may be secured togetherto prevent unauthorized relative movement thereof.

JOSEPH A. CLINTON.

